Sheriff's helicopter pilot Dave Weldon has replayed the scene again and again. And he wonders: How could the worst blaze in California history have been prevented?

At 5:45 p.m. Saturday, Weldon and his partner spotted smoke as they flew toward Cleveland National Forest in search of a missing hunter.

They radioed in an urgent request: Send air support immediately, they told the dispatcher – either a water-dropping helicopter or a tanker with a load of fire retardant.

The request was denied by a U.S. Forest Service official.

The reason? It was almost sunset, and state and federal regulations require firefighting aircraft to land 30 minutes before sunset, which that night was 6:06 p.m. After dark, the risk of crashing increases.

Weldon told his partner, Rocky Laws, to make another plea, this time to a sheriff's helicopter en route to Balboa Park that was carrying a large water bucket.

That helicopter took off immediately.

But five minutes away from the fire, the pilot was ordered by a U.S. Forest Service official to turn back because the sun was going down.

By nightfall, Weldon and other witnesses watched from various vantage points as the small brush fire grew into an unprecedented disaster.

How, exactly, did the fire begin?

Would more resources have kept it from spreading so widely?

Might the blaze have been doused if a helicopter or air tanker had been allowed in immediately?

Investigators will ponder those questions in the weeks and months ahead. They may never get all the answers.

But they will find clues in the accounts of those who first glimpsed the orange streaks, the plumes of smoke and, finally, the giant flames. The hikers on a mountain ridge to the east. The nervous residents of an upscale community to the west of the national forest who called 911. And the firefighters and helicopter pilots who will always wonder if there was anything more they could have done.

JoAnne Robertson and her husband, Richard, were walking out the door of their home in San Diego Country Estates about 5:30 p.m. when they saw a small ring of flames in the distance.

A 911 operator assured them help was on the way.

In the three decades since their custom home development was built on the outskirts of Ramona, houses there had been scorched but never destroyed. So the Robertsons went to dinner, believing the fire would be out by the time they returned.

Their next-door neighbor, Carolyn Berg, noticed a tiny curl of smoke about 15 minutes later, when she was carrying in groceries. It seemed to be about half a mile away.

Berg and her husband huddled with neighbors. One already had called the California Department of Forestry and Fire Protection, known as CDF. Then they settled down to wait – and watch.

Helicopter pilot Weldon and his partner had just rescued an Alzheimer's patient in Oceanside when they were told of the lost hunter in the Cleveland National Forest – an area they know well. Over the summer, they helped rescue dozens of people there.

As they headed out to find West Covina resident Sergio Martinez, they got another message from the dispatcher: There were reports of smoke.

Laws spotted a small plume and Weldon maneuvered the helicopter toward it, about a mile south of Eagle Peak Road. They saw flames and told dispatchers the fire covered approximately 50 square yards, about the size of 1½ basketball courts.

Twice, Laws tried to radio crews at the Ramona airport, where the CDF and the U.S. Forest Service share an air base.

But because the CDF and the Sheriff's Department use different radio frequencies, he couldn't reach the ground crew.

"I said to Rocky, 'With the winds coming so strong from the east, at about 20 to 30 mph, this thing has the potential to get very bad,' " Weldon recalled. "He said, 'I know.' "

At 5:46 p.m. Weldon set his helicopter down on a steep slope covered with chaparral. Laws radioed the sheriff's dispatcher in Kearny Mesa, asking for CDF air support from Ramona airport. The request was denied by the Forest Service.

He also called for the sheriff's helicopter that was en route to Balboa Park, which headed northeast immediately but was soon called back. Gene Palos, who was flying the helicopter, did as he was told – reluctantly.

"I'm sure I could have gotten three drops in," he said. "Who knows? Anything is better than nothing."

Laws hiked about 75 yards to where Martinez, who had been lost for 11 hours, was waving.

The hunter was delirious and couldn't walk, so Weldon left the helicopter and helped drag and carry him through the thick chapparal that ripped at their clothing and stood more than 12 feet tall.

Weldon said that as he and Laws lifted Martinez into the helicopter, Martinez said, "I'm sorry. I'm sorry about all of this."

Weldon asked the hunter how he had started the blaze.

"He just remained quiet," Weldon said.

"Then he said: 'I thought I was going to die out there. Thanks for saving my life.' "

When the helicopter took off at 6:21 p.m., they could feel the heat from the fire.

Donna Jennings, a retired geophysicist, was spending the weekend with friends in a Cuyamaca mountaintop cabin. As sunset approached, they hiked around the west side of the peak. They shared a bottle of champagne and enjoyed the view.

Suddenly, a wall of flames as tall as a building shot up on a ridge. It looked to Jennings as if it was about 2 miles away.

Smaller, separate fires broke out upwind from the flames.

One of her friends hiked ahead to call for help from his cabin, while the rest of the group watched helplessly.

At 5:37 p.m. the CDF notified the U.S. Forest Service that fire had sprung up in a ravine in the Cleveland National Forest, near Cedar and Boulder creeks, not far from the San Diego River.

Michelle Sarubbi, a Forest Service officer on duty, rushed toward the fire in a sport utility vehicle.

At least 20 engines and two crews with 20 elite firefighters each were on their way less than 15 minutes later, according to the forest service log for that day.

By 7:06 p.m., the first engines had pulled into the area, but they couldn't get to the fire. It was burning at midslope of a steep incline cluttered with boulders, brush and small oaks.

"We had engines driving around like crazy trying to figure out how to get in there," Sarubbi said.

Cleveland National Forest Fire Chief Rich Hawkins was sitting down to dinner near Fallbrook with CDF Division Chief Bill Clayton when they heard frantic chatter on their scanner. There was a fire near Cedar Creek.

"We instantly knew that this was going to be terrible," Hawkins said. "It started in the same area as the 1956 Inaja fire where many firefighters died. We both looked at each other and I said, 'I've got a bad feeling about this.' "

Hawkins and Clayton already were on edge. For the past few days they'd been fighting a brush fire that had started on Camp Pendleton and burned about 5,000 acres of brush as it headed toward the communities of Fallbrook and De Luz. They'd also sent firefighters to the massive fires burning in Riverside and San Bernardino counties.

The hot, dry Santa Ana winds fueling those fires were forecast to blow into a San Diego County landscape devastated by years of drought and thousands of dying, diseased trees.

Red-flag warnings for critical fire danger had been posted throughout the county the day before. Burn permits had been suspended and all CDF firefighters called back to work. The CDF reactivated five of the 10 air tankers it had sent for winter maintenance just a week earlier.

The two fire chiefs left quickly, taking 20 engines and two hand crews with them.

Sometime after 7 p.m., when they arrived at the site of the new fire, about a half-dozen fire engines already were trying to get to the bottom of the San Diego River canyon where the fire was being fanned by erratic winds.

It was a situation veteran firefighters know is the most dangerous in wild-land fires.

"We're working our way downhill to a fire that wants to burn uphill, and we all know that historically that is how we kill firefighters," Hawkins said.

By 9 p.m., a couple of engines had made their way to the bottom of the riverbed. "It looked like we had a shot at it," Hawkins said.

Within minutes, however, his hope turned to dismay.

"When we got down there, we realized that the fire was a heck of a lot farther away then we thought," he said. "That's when we knew we were basically screwed."

About 15 minutes before midnight, the winds picked up and the fire jumped the river, starting its howling march up the canyon toward San Diego Country Estates and Barona Mesa, a community just north of the Barona Indian Reservation.

By early morning, Hawkins said, the fire was consuming 6,000 acres an hour. The winds were gusting up to 70 mph in some canyons and ridge tops. Any moisture had been squeezed from the air.

Fearing the worst, and knowing they already were losing homes, Hawkins and Clayton put firefighters in places where lives were endangered.

"Sunday was the worst day of my life," Hawkins said, recounting his reaction to news of the first deaths. "We have all had tears running down our faces on and off."

At midnight the Bergs were still in their house, watching the fire divide into two small, blazing lines. Soon the sky turned pink.

About 2 a.m., Carolyn Berg said, the hillside exploded into flames "right in front of me."

A neighbor drove up and down the street yelling for everyone to get out. Berg's husband wakened the elderly couple across the street and told them to leave.

The fire spread up the hill and began swallowing houses as the Bergs frantically packed their bags.

"It was like a freight train coming down the street," Carolyn Berg said. "My husband just yelled 'Run!' and we just jumped in our car and took off. It came so suddenly it was like a wall of flames."

Berg saw other residents fleeing from San Diego Country Estates, but saw no firefighters or sheriff's deputies.

"We just fled on our own," she said. "We thought that someone would come and evacuate us, but no one did."

Berg's fear was mixed with anger.

"We notified the people we thought should be notified, and no one came," she said. "I'm convinced that if one (water) drop had been made on that fire when we called, this all would have been prevented."

As the couple drove away, Berg looked back at the house she and her husband had bought just nine months ago.

"I thought, there goes my dream. I thought I'd never see it again."

The Robertsons were escaping, too. About 1 a.m., their daughter Robin, who had gone out for the evening, called on her cell phone to warn them the fire was spreading. By about 3 a.m., they realized they had to leave.

"People were running around like birds let out in a house batting off the walls," Robin Robertson said.

For the first 48 hours of what is now known as the Cedar fire, chiefs Hawkins and Clayton and other fire officials identified areas that needed to be evacuated and passed the information along to law enforcement agencies, which are responsible for evacuations.

The firefighters moved from spot to spot. Because the fire's strength kept them on the defensive, they made few pre-emptive strikes.

Finally, Hawkins decided to abandon about 22 miles of potential fire lines in the mostly uninhabited area that stretches from San Diego Country Estates to Julian. He didn't have enough firefighters to go around.

By Wednesday, with the Cedar fire still raging out of control, Sarubbi and a team of Forest Service investigators finally were able to hike into the charred area where Sheriff's pilot Dave Weldon had rescued the hunter five days earlier.

The team's goal was to gather clues to determine how the fire began. They also have been examining hundreds of pages of reports filed by firefighters who documented the spread of the fire.

On the day of Martinez's rescue, he was given a misdemeanor citation and released. But if investigators decide his signal fire ignited the biggest wildfire in state history – and they can show negligence – additional charges could be filed.

In the tightknit community of firefighters and forest service officers, meanwhile, a heated debate is brewing.

Some pilots, including Weldon and Palos, believe the regulations should be changed to allow water drops during twilight if pilots think it's safe.

But others like Sarubbi contend that strict regulations prevent catastrophes.

"When you fly at night with low elevation and timber and smoke, it's easy – very easy – to get disoriented. You just cannot see the hazards," said Mike Apicello, spokesman for the National Interagency Fire Center in Boise, Idaho.

And it's very easy for a fire to spiral out of control.

"Everybody is really suffering today," Hawkins said Wednesday night, his voice cracking. "I freaked out over the kids dying and the adults dying and then the firefighter dying. I'm going to be grieving over this for a long, long time."